I have a background of Amazon VA and have been doing this for 1 year Including whole launches from Product research to Ranking.
I can work with you and merge your variations into parent lisiting so when the buyer will search the product, all the variations will be shown to him/her together.
Secondly, it will rank the best selling variation and all others will be ranked automatically. Means it will save your budget in ranking.
I will give you Free mock-up consultation to show you my ability.